<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<style>
    .float {
        float: left;
    }

    .father {
        background-color: aqua;
    }

    .clearfix::after {
        content: "";
        visibility: hidden;
        display: block;
        clear: both;
        height: 0px;
        font-size: 0px;
    }

    .clearfix {
        zoom: 1;
    }

    .son {
        background-color: yellow;
        width: 100px;
        height: 100px;
        margin: 10px;
    }

    .uncle {
        background-color: chartreuse;
        width: 100px;
        height: 100px;
    }
</style>

<body>
    <div class="float uncle"></div>
    <div class="father clearfix">
        <div class="son float"></div>
    </div>

</body>

</html>